Defence Institute of Physiology and Allied Sciences, Defence Research & Development Organisation, Ministry of Defence, Government of India, Lucknow Road, Delhi, 110054 India.
Retired from- Institute of Nuclear Medicine andAllied Sciences, Defence Research and Development Organization, Ministry of Defence, Government ofIndia, Delhi, India.
Mil Med Res. 2017 Feb 17;4:6. doi: 10.1186/s40779-017-0113-x. eCollection 2017.
The present study was designed to evaluate load carriage performance at extremely high altitudes with different loads and walking speeds in terms of physiological evaluation. The degree of maximum oxygen consumption changes at high altitudes was also examined.
Twelve Indian Army soldiers were acclimatized at altitudes of 3,505 m and 4,300 m. They walked for 10 minutes on a motorized treadmill at 2.5 km/h and 3.5 km/h speeds during carrying no loads and three magnitudes of load (10.7 kg, 21.4kg, 30 kg) at both altitudes. Physiological parameters such as oxygen consumption, energy expenditure, heart rate, and ventilation were recorded for each breath using a gas analyzer. The rating of perceived exertion was also noted after each load carriage session. Maximal oxygen consumption (VO) was measured at sea level and the two high altitudes, and respective relative workloads (% of VO) were calculated from oxygen consumption. Repeated measure ANOVA was applied to reveal the significant effects of the independent variables.
The participants had significant reductions in VO with rising altitude. Marked increases in almost all physiological parameters were observed with increasing load, altitude, and speed. The soldiers expressed heavy perceived exertion levels with higher loads at 3.5 km/h at the two high altitudes.
Considering the physiological responses, expressions of perceived exertion and changes in relative work load at both of the high altitudes Indian soldiers are advised to walk slowly with adequate rest in between their schedules and to carry not more than 32% of their body weight.
本研究旨在评估在不同负荷和行走速度下，在极高海拔地区的负重表现，从生理学角度进行评估。还检查了高海拔地区最大摄氧量的变化程度。
12 名印度陆军士兵在海拔 3505 米和 4300 米处适应环境。他们在电动跑步机上以 2.5 公里/小时和 3.5 公里/小时的速度行走 10 分钟，在两个海拔高度下不携带任何负荷和携带三种负荷（10.7 公斤、21.4 公斤、30 公斤）。使用气体分析仪记录每一次呼吸的氧气消耗、能量消耗、心率和通气等生理参数。在每次负重后还记录了感知用力程度。在海平面和两个高海拔地区测量最大摄氧量（VO），并根据氧气消耗计算相应的相对工作量（VO 的百分比）。应用重复测量方差分析揭示独立变量的显著影响。
参与者的 VO 随着海拔的升高而显著降低。随着负荷、海拔和速度的增加，几乎所有生理参数都明显增加。士兵们在两个高海拔地区以 3.5 公里/小时的速度表示出更高负荷的沉重感知用力水平。
考虑到生理反应、感知用力的表达以及两个高海拔地区相对工作负荷的变化，建议印度士兵在行走时速度要慢，在行程之间要有足够的休息时间，并且携带的负荷不要超过体重的 32%。
